Listers are special segment collections which allow to show some list of
segments for each entity in the list of entities (multiply their segments list
by a list of entities). E.g. powerline.listers.vim.tablister presented with
powerline.segments.vim.tabnr and ….file_name as segments will emit
segments with buffer names and tabpage numbers for each tabpage shown by vim.

Sets the segment info values of workspace and output to the name of
the i3 workspace and the xrandr output respectively and the keys
"visible", "urgent" and "focused" to a boolean indicating these
states.

Parameters:

only_show (list) – Specifies which workspaces to list. Valid entries are "visible",
"urgent" and "focused". If omitted or null all workspaces
are listed.

output (str) – May be set to the name of an X output. If specified, only workspaces
on that output are listed. Overrides automatic output detection by
the lemonbar renderer and bindings. Set to false to force
all workspaces to be shown.